Ionospheric response to the 08 April 2024 total solar eclipse over United States : a case study

A total solar eclipse occurred on April 8, 2024, across the United States, with obscuration rates ranging from 20–100% at different locations. We study the ionospheric Total Electron Content (TEC) response to the eclipse using data from 51 ground-based GPS stations. We find a significant depletion in TEC of up to 65%, with larger depletion rates occurring along the path of totality. We also observe a time delay between the maximum TEC depletion and the time of maximum obscuration, ranging from 8 to 80 minutes, with longer delays occurring at stations with lower obscuration rates. Both time delay and TEC depletion rates are found to vary with latitude, with slightly longer delays at lower latitudes and higher TEC depletion rates at mid-latitudes. The TEC depletion rate also increased with local time, showing a higher decrement after noon compared to before. The spatiotemporal variation in TEC closely followed the eclipse’s path, indicating a positive correlation with the movement of the moon’s shadow. Monitoring rate of TEC change during such rare events is crucial for enhancing our understanding of ionospheric dynamics, which can be very helpful to improve the accuracy of global communication and navigation systems.